By Melissa Hogenboom
29 April 2016
Five hundred thousand years ago a hyena was munching on the remains of one of our early human ancestors.
It was damaged, broken and had been chewed
More specifically, it was tucking into the thigh bone of an individual believed to belong to the prehistoric species Homo rhodesiensis,thought to be the common ancestor of both our species and the Neanderthals.
The human remains were found resting in a cave in the suburbs of what is now Casablanca in Morocco, an area known to be rich in fossils.
The femur bone was uncovered in a layer of sediment known to be half a million years old. It was unearthed in excavations in 1994 but only “rediscovered” over a decade later.
“It was damaged, broken and had been chewed,” says Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
Such was the damage that it was not even immediately identified as an early human fossil. “On second look we saw it was a human femur,” he says.
The team performed detailed analysis of the tooth marks – which were observed at both ends of the bone – to understand more about the fate of the early human it belonged to.
The dimensions of the tooth marks suggest they were made by a large carnivore.
Fossil evidence from the cave shows it was also a lair for extinct relatives of modern hyenas – although not at the same time that early humans occupied the cave.
The presence of carnivore tooth-marks on human remains is not sufficient to demonstrate predation
“It looks like the cave has been used by humans and also carnivores, so there is a physical proximity between the two groups,” says Hublin.
Putting two and two together, it makes sense that an ancient hyena caused the damage, the team report in journal PLOS ONE.
The exact form of the bone fractures is also most consistent with damage by a hyena, says lead author Camilla Daujeard from the National Museum of Natural History in Paris, France.